The kidney is a target of toxicity from drugs, and industrial and environmental chemicals because of its high blood flow, numerous transporters, and reliance on aerobic metabolism. Not surprisingly, mitochondria are a common intracellular target of chemicals in multiple organs, leading to decreased aerobic metabolism and ATP, and cell death. Current in vitro models of nephrotoxicity and mitochondrial damage are inadequate for many of the same reasons: cultured cells are very glycolytic with minimal aerobic metabolism, and there are no moderate or high-throughput real-time metabolomic assays. Consequently, new cellular models and metabolomic methodologies are needed to evaluate nephrotoxicity and mitochondrial damage. We have developed primary cultures of renal proximal tubular cells (RPTC) that exhibit in vivo levels of aerobic metabolism, are not glycolytic and retain higher levels of differentiated functions. We previously developed primary cultures of renal proximal tubular cells (RPTC) that exhibit in vivo levels of aerobic metabolism, are not glycolytic, and retain higher levels of differentiated functions. The goal of the Phase I proposal was to merge our novel and relevant RPTC model and the Seahorse technology to develop a high-throughput assay to accurately measure nephrotoxicity. In addition to completing the objectives described in the Phase I aims, we also developed a cheminformatic strategy in which chemical similarity is used to cluster molecules that are then modeled to define a potential toxicophore of similar physicochemical features in 3-dimesional space. These chemical entities/toxicophores that damage mitochondria are predicted to be nephrotoxicants. Our goals for Phase are to validate our integrated metabolic and imaging assay using the TOXNET & Toxcast land to use cheminformatic analyses to develop a toxicophore database. This RPTC/Seahorse platform will identify nephrotoxicants and mitochondrial toxicants and provide public companies and regulatory agencies with mechanism and chemical-based criteria for assessing and predicting nephrotoxicity and mitochondrial toxicity of new drugs, consumer products, and environmental agents, and shorten the overall time to identify potential problem chemicals. The commercialization plan is to offer these screening and cheminformatic services to pharmaceutical & federal agencies.